Why do fire alarms go off falsely? What can you do to prevent it?

Why should false alarms be taken seriously?

In a building with frequent false alarms, people get used to the siren. The first few times everyone goes outside; then they do not, and then someone learns how to silence the panel. When a real fire breaks out, the occupants may take the siren for one more false alarm.

A false alarm also shows that something in the system has a problem. If a dirty detector gives a false alarm today, tomorrow it may detect real smoke late. That is why every false alarm should be treated like a fault report.

If the panel is connected to a monitoring center or the fire department, frequent false alarms also send crews out for nothing. Alarms that come one after another after a dust storm in Şanlıurfa, or at hot midday hours in summer, are a sign that the system does not suit its environment.

The most common causes

Most of the false alarms we meet on site come from a few familiar causes:

• Steam: smoke detectors near bathrooms, showers, dishwashers and tea corners
• Cooking smoke: a smoke detector fitted in the kitchen or at the kitchen door
• Dust: renovation, construction, sanding and dusty storage areas
• Dirty detector: devices that have not been cleaned for years and have collected dust and insects
• Cigarette and hookah smoke: smoking on the quiet in areas marked no-smoking
• Heat: a heat detector of the wrong temperature class in a hot attic or technical room
• Cable and device faults: a junction box that has taken in moisture, a loose connection, a detector at the end of its life
• A manual call point pressed on purpose or by accident

How do you find the cause?

The first step is the panel log. Addressable panel shows the device that raised the alarm by name; the date and time are also in the record. On a conventional panel you see which zone the alarm came from, and to find the device you look for the detector with its alarm light on in that zone.

Then look for a pattern. Does the alarm always come from the same detector? Always at the same time, for example at lunch or at morning shower time? Does it coincide with cleaning day, renovation work or rainy weather? These questions often point straight to the cause.

If alarms come from different points with no particular order, the problem may be in the cable line, the panel or the power supply. In that case the maintenance company needs to measure the line.

The panel's event log can fill up and older records get deleted. In buildings with frequent false alarms, copying the records into a notebook at regular intervals makes the pattern easier to see.

Expert note: When a false alarm happens, photograph the panel screen or the log with your phone. The date, time and device details help the maintenance technician find the cause faster. When you take notes, also write down what was going on in the area at that moment.

Lasting solutions

Once the cause is found, the fix is usually simple. A smoke detector in the kitchen is replaced with a heat detector. A detector right next to the bathroom door is moved a few steps away. A dirty detector is cleaned or replaced with a new one. For a room with a tea corner, a multi-sensor detector is considered.

For dusty areas, a detector type suited to the area is chosen. If the dust is very heavy, a heat detector or an aspirating system with a filter is considered. If a heat detector in a hot attic gives alarms at midday, the detector's temperature class is selected again to suit the environment.

If the button is pressed by accident or as a joke, a protective cover is fitted to the button. Moving or removing the button is not right; the button must stay on the escape route.

Some addressable panels offer features such as alarm verification for certain detectors, or different sensitivity settings for day and night. These settings can reduce false alarms but also affect the time it takes to detect a fire. They must be done only in line with the fire project and the manufacturer's instructions, by a competent technician.

What should be done during renovation work?

Renovation is one of the most common causes of false alarms. Sanding, cutting and paint dust trigger smoke detectors. Talk to your maintenance company before the renovation starts. Dust covers can be fitted to the detectors in the work area, or that zone can be temporarily disabled from the panel.

Pay attention to two things here. For the disabled area, another precaution must be considered for that period, such as keeping a fire extinguisher at hand or leaving a person on duty in the work area. When the work is finished, the covers must be removed and the zone put back into service. Disabling and restoring must be recorded with date and name.

When painting, make sure the detectors are not painted over. A painted detector no longer detects smoke and has to be replaced.

The first minutes when the alarm sounds

When the alarm sounds, do not assume it is false. First check on the panel which zone or device raised the alarm, and check that point on the spot. If you see smoke, smell something or feel heat, start the evacuation and call the fire department.

If you see nothing on the spot and the cause is clear, for example steam in the kitchen or renovation dust, you can silence and reset the panel. If the cause is not clear, consult the maintenance company before resetting the system. If the same detector gives an alarm again right after the reset, take that point seriously.

It must be decided beforehand who will go to the panel, who will check and who will make the decision. In buildings with a night attendant, this person should be shown briefly how to use the panel.

What should not be done

Building managements tired of false alarms sometimes resort to shortcuts. Every one of these leaves the system useless and can create serious liability in the event of a fire. If you are unsure about the regulations, consult an expert.

• Permanently disabling the panel or a zone
• Leaving a bag, tape or a cover over a detector
• Pulling out the siren cable or silencing the siren and leaving it that way
• Removing a faulty detector without fitting a new one in its place
• Turning off the panel's audible warning and ignoring the fault light

Frequently asked